Tuesday, 6 November 2018

East Anglia's changing climate

6 November 2018

Last week, the Met Office published a report looking into the UK's changing climate, in conjunction with its State of the UK Climate 2017 report. Both studies confirm that the climate of the UK as a whole has become notably warmer, slightly wetter and marginally sunnier, compared to the long term average.

Temperature

In East Anglia, the average annual mean temperature during the past decade (2008-2017) has increased by 1.0°C compared to the climatological 30-year average (1961-1990). While all months have experienced a warming trend, it is most pronounced during the spring, especially the month of April where the mean temperature has increased by nearly 1.4°C. December has seen the smallest increase of any month, at 0.6°C.
Our warming climate has also resulted in a reduction in the frequency of frosts, with approximately 8 fewer air frosts in an average year - a decrease of 16%. In a record which spans nearly 100 years (back to 1910), 8 of the top 10 warmest years in this region have all occurred since 2000.

Rainfall

Rainfall in the region has increased by just over 3% compared to the 1961-1990 baseline, translating to an extra 20mm or so in an average year - and while this figure may seem small, it masks a lot of variation throughout an average year. Summer is now 16% wetter, with August seeing a 23% increase in its average rainfall. Conversely, spring has become drier than normal with nearly a 13% reduction in rainfall - April in particular now produces 28% less rainfall than in the past.

Change in rain days (≥1mm in a day) between 2008-2017 and 1961-1990 averages (Data: Met Office)

Sunshine

Sunshine hours increased by just over 7% during the past decade in East Anglia, equating to an extra 111 hours of sunshine in an average year compared to climatology. The biggest increases have been during the winter and spring seasons, both at approximately 15%, while there has been little change in summer and autumn. Once again, April has experienced the largest increase at 28%, while June and October are the only two months to witness a (small) reduction in sunshine hours, at approximately 1%.

Summary

To summarise, the climate of East Anglia has become warmer. Summer is now, on average, notably warmer and wetter than in the past, while spring has become significantly drier and warmer, and slightly sunnier. Winter has also seen a slight increase in sunshine hours. Overall, April has experienced the biggest change in climate than any other month.